Kinopi serves as Belt Satan's primary enforcer and second-in-command, disseminating the demon ruler's orders across the Land of Wonders and actively thwarting the protagonist's attempts to rescue Nina. His name reflects his origins as a non-sentient mushroom before Belt Satan's transformative magic granted him intelligence and mobility, binding his existence to the demon's power. Throughout his service, Kinopi endures consistent mistreatment and verbal abuse from Belt Satan, especially following failures against Paul and his companions. Despite unwavering loyalty, Belt Satan eventually deems Kinopi expendable after deciding on open warfare, attempting to execute him.

Surviving this betrayal, Kinopi is found and nursed back to health by Paul's group. Their kindness motivates his defection. He joins forces with Paul, Pakkun, and Doppe, providing vital tactical knowledge against Belt Satan's forces during the final battle. Kinopi understands his sentient life remains intrinsically tied to Belt Satan's magic, meaning the demon's defeat will inevitably end his own existence. After Belt Satan falls, Kinopi rapidly weakens, expressing gratitude for the chance to achieve profound redemption before permanently reverting to his original state as a non-communicative toadstool.